Conventional and Real-Time PCR Targeting blaOXA Genes as Reliable Methods for a Rapid Detection of Carbapenem-Resistant Acinetobacter baumannii Clinical Strains

Dagmara Depka; Agnieszka Mikucka; Tomasz Bogiel; Mateusz Rzepka; Patryk Zawadka; Eugenia Gospodarek-Komkowska

doi:10.3390/antibiotics11040455

Conventional and Real-Time PCR Targeting bla_OXA Genes as Reliable Methods for a Rapid Detection of Carbapenem-Resistant Acinetobacter baumannii Clinical Strains

Antibiotics (Basel). 2022 Mar 28;11(4):455. doi: 10.3390/antibiotics11040455.

Authors

Dagmara Depka¹, Agnieszka Mikucka¹, Tomasz Bogiel¹, Mateusz Rzepka¹, Patryk Zawadka¹, Eugenia Gospodarek-Komkowska¹

Affiliation

¹ Microbiology Department, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Toruń, 85-094 Bydgoszcz, Poland.

Abstract

Multidrug-resistant Acinetobacter baumannii, particularly those producing carbapenemases, are spread worldwide. A reliable detection of carbapenemases is essential to choose the appropriate antimicrobial therapy and, consequently, prevent the dissemination of carbapenem-resistant strains. The aim of this study is to examine the molecular basis of the carbapenem resistance mechanism and estimation of conventional PCR and real-time PCR usefulness for the detection of oxacillinases when compared to phenotypic carbapenemases detection. The following methods were evaluated: the CarbAcineto NP test, Carbapenem Inactivation Method, CPO panels of semiautomated antimicrobial susceptibility testing method on the BD Phoenix™ M50 system, conventional Polymerase Chain Reaction and real-time PCR. The eazyplex^® SuperBug complete A assay was used as the reference method. Among the tested strains, 39 (67.2%) carried the bla_OXA-40 gene, while the bla_OXA-23 gene was noted amongst 19 (32.8%) isolates. The diagnostic sensitivities of the studied assays were as follows: CarbAcineto NP-65.5%; CIM-100%; CPO-100%; conventional PCR-100%; real-time PCR-100%.

Keywords: Acinetobacter baumannii; OXA-23; OXA-40; OXA-like beta-lactamases; OXA-like carbapenemases; carbapenem-resistant; carbapenemases; resistance to carbapenems.